Nakaya Manabu, Ohtani Ryo, Sugimoto Kunihisa, Nakamura Masaaki, Lindoy Leonard F, Hayami Shinya
Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto, 860-8555, Japan.
Research & Utilization Division, Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan.
Chemistry. 2017 May 29;23(30):7232-7237. doi: 10.1002/chem.201700593. Epub 2017 Apr 10.
The nature of the molecular assemblies formed in the crystalline state by cobalt(II) terpyridine (terpy) complexes incorporating appended adenine (A) or thymine (T) bases was found to be controlled by which bases are present. Single-crystals of the cobalt(II) complexes Co(A-C6-terpy) (1) and Co(T-C6-terpy) (2) have needle and block habits, respectively. Subsequent mixing of 1 and 2 in MeOH resulted in isolation of Co(A-C6-terpy) (T-C6-terpy) (3) as plate-like crystals. A 3D network structure is present in 1 that incorporates 1D chains, whereas 2 adopts a 2D stacked structure constructed from ladder-type assemblies. For 3, "dimer-rings" consisting of [Co(A-C6-terpy) ] and [Co(A-C6-terpy)(T-C6-terpy)] units are generated by means of base-pairing between A and T. Notably, 3 displays the first crystal structure of a heteroleptic cobalt(II) complex of Co(A-C6-terpy)(T-C6-terpy) . These assembly differences involving the terpyridine cobalt(II) complex units in 1-3 affect the cooperativities influencing their spin crossover (SCO) behavior. The influence of the terminal nucleobases on the resulting assembly has been probed by investigating the co-crystallization of Co(terpy) (4) with Co(C6-terpy) (5) and 1 with 5.
人们发现，由结合了附加腺嘌呤（A）或胸腺嘧啶（T）碱基的钴（II）三联吡啶（terpy）配合物在晶体状态下形成的分子聚集体的性质受存在的碱基种类控制。钴（II）配合物Co(A-C6-terpy)（1）和Co(T-C6-terpy)（2）的单晶分别具有针状和块状习性。随后在甲醇中将1和2混合，得到了板状晶体Co(A-C6-terpy)(T-C6-terpy)（3）。1中存在包含一维链的三维网络结构，而2采用由梯型聚集体构建的二维堆叠结构。对于3，由[Co(A-C6-terpy)]和[Co(A-C6-terpy)(T-C6-terpy)]单元组成的“二聚体环”通过A和T之间的碱基配对生成。值得注意的是，3展示了Co(A-C6-terpy)(T-C6-terpy)杂配钴（II）配合物的首个晶体结构。1 - 3中涉及三联吡啶钴（II）配合物单元的这些聚集体差异影响了影响其自旋交叉（SCO）行为的协同性。通过研究Co(terpy)（4）与Co(C6-terpy)（5）以及1与5的共结晶，探究了末端核碱基对所得聚集体的影响。
